Engine



Jan. 1 7, 1947. c. E. FRANK ENGINE Filed Dec. 24, "1943 3 Sheets-Sheet 1 A m a W n 4 i4 1 a 7 1 1 w 2 a 9 4 l y !/u////////// ////////X//// x 4. l Y .i o i I k ew mm%, x ii 3 5% a fl L X.

C. E. FRANK Jan. 7, 1947.

ENGINE 3 Sheets-Sheet 2 Filed Dec. 24, 1945 flare/70 INVENTOR.

zen W Jan. 7, 1947.

ENGINE Filed Dec. 24,1943 :s Sheets-Sheet INVFNTOR. Clare/ ce Zfi fl &-

HTToF/VEYJ.

c. E. FRANK 2,413,820,

Patented Jan. 7, 1947 UN TED-STATES T NT-e s ENGINE Clarence E. Frank, Fraser, Mich asslgnor to Briggs Manufacturing Company,

Detroit,

Mich., a corporation of Michigan This invention relates to-internal combustion engines and especiallytoenginesof the class having rotatable valves in the cylinderhead providing substantial portions of the combustion space at the time of firing. In particular the present invention principally contemplates the cooling of Application December 24, 1943, Serial No. 515,479

' 19 Claims. (crux-soy maintaining greater uniformity in the operating I clearance between the valve and its bearing sursuch engines and the provision of meansfor controlling the expansion of portions of the cylinder v head adjacent the rotatable valve so-as to maintain more closely or accurately the desired operating clearances between the valve and related bearing surfaces in the cylinder head.

An object of the invention is to provide an improved internal combustion engine which may be liquid cooled in efflcient manner and will be compact and relatively simple in construction as well as easy to assemble.

A further object of the invention is to provide an engine having a rotatable valve and improved means for controlling'the relative expansion of i the valve and cylinder head due to heating of associated portions thereof during operation.

Another object of the invention is to, provide an engine having a cylinder, cylinder head and Y a rotatable valve in the head,-such asa generally frusto-conical valve, and in which means are provided for maintaining closely predetermined operating clearances between the valve and head,

especially where the valve and headare made of metals or metal alloys having different thermal appreciablerelative expansion of the head and valve at localities where it .is desired to maintain substantially constant clearances between adjacent bearing surfaces of the head and valve.

A further object of the invention is to provide a cylinder head constructed for mounting and operation therein of a rotatable valve, preferably of frusto-conical shape, and in which the cylinder head is constructed in improved manner-to provide efficient cooling of the valve and its associated parts as well as the exhaust conduit by means of a liquid coolant.

Another object of the invention is to provide improved means for assembling and attaching together the cylinder and cylinder head, the same being accomplished in such improved manner as to effect control of the expansion of the housing for the rotatable valveduring operation, thereby faces and reducing loss of lubricant due to leak age past such surfaces It is also anobl'ect ofthe invention to provide an engine havinga cylinder headand a valve rotatable therein and having a different, such as a small'encceflldient of expansion than the head and in which means is provided whereby the rate of expansion of the head will be sub-- stantially the same as the valve at certain bearing localities whereit is desirable to maintain uniform operating clearances between the cooperatw ing bearing surfacesv ofthe valve and head,

Other objectsof this invention will appear in the followingdescription and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

Fig. 1 is a fragmentary sectional elevation illustrating a portion of a multi-cylinder engine.

Fig. 2 is a fragmentary sectional elevation illustrating a portion ofthe driving mechanism for I i the rotatablevalve or valves of theengine. -Fig. 3-is, a section taken substantially through lines 33 of Fig. 1 looking in the directionof the arrows. 5 iv Fig. 4 is a fragmentary sectional view taken substantially through lines 4401' Fig.1 looking in the direction of the arrows.

Fig. 5 isa fragmentary sectional elevation illus; trating another embodiment of the present invention.

Before explaining in detail the present invention it is to be understood that the invention is .not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying. drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employedherein is for the purpose of description and not of limitation,

The present invention is especially applicable to engines of the class having rotatable valves,

' preferably but not necessarily rotating continuously in one direction, for controlling-the intake and firing of the fuel charge and for exhausting the products of combustion. In theillustrated embodiment of the invention, exemplifying one desirable adaptation thereof, a rotatable valve of the frusto-conical type is mounted in the cylinder head and is formed withsubstantially all or at least the maior portion of the combustion the spark ignition type.

'the cylinder is formed at its inner side forming of the'wall portion 3| opening or port in the side of the valve adapted to register with intake and exhaust passages and an ignition device during operation, there being an opening or port at the innerv end or bottom of the rotor communicating at all times with the cylinder.

In the drawings I example, certain as applied to an internal combustion engine of However, it will be understood that the invention is not limited to an engine in which combustion is initiated by spark ignition. For most uses ti-cylinder type but for the purposes of simplification a single cylinder unit of the engineis illustrated in the present embodiment, it being understood that the remaining cylinders and associated this gasket will provide a liquid and gas tight joint. 1

The cylinder head is formed with a series of lugs or ribs 36. and 31 bored to receive bolts 38 extending from bosses (not shown) on the jacket member 24 which,as stated, is fixed to the crankhave illustrated, byway of embodiments of the inventionv the engine'is of the mulparts are identical to the structure herein shown and described.

Referring to the drawings, they present engine comprises a cylinder within which a suitable piston 2| is mounted for reciprocation. The piston is connected in the usual manner through a wrist pin 2|a and connecting rod 22 to the crankshaft 23 of the engine. Surrounding the cylinder 20 is a cylindrical jacket 24 which is rigidly secured to the crankcaseor forms substantially an integral portion of the crankcase. This jacket member 24 has an extended portion spaced from the wall of the cylinder 20 to provide a water cooling space or chamber 25 extending entirely around the cylinder. The lower or inner end of the cylinder 20 is formed with an annular rib 20a forming a pilot portion slidable into and having a smooth fit within the inner cylindrical wall of the lower section 24a of the jacket member 24, the rib 20a carrying sealing rings 25 to prevent leakage of taposed surfaces of the portions 20a and 24a.

The engine is provided with a cylinder head 21 which is cast with a depending wall or skirt 28 terminating adjacent the outer end of the cylinder and spaced therefrom to provide a liquid cooling space or chamber 29 adapted to form a continuation of the chamber 25. When the cylinder head is assembled the lower edgeof the skirt or jacket portion 28 is drawn down tightly against the upper thickened edge 24b of the jacket member 24, there being a gasket 30 interposed between the juxtaposed surfaces of those portions adapted to be compressed'to provide a liquid tight joint.

In the embodiment of Fig. -1 the outer end of with an outwardly extending annular flange 20b extending in juxtaposed relation to an annular wall portion 3| of the cylinder head. The annular flange2|lb of the cylinder is formed with a vertical shoulder or abutment33. The lower edge of the wall portion 3| of the cylinder head is formed with an annular rib 34 which fits into the recess 32 and abuts against the shoulder 33. The upstanding annular portion of the flange 20b,which surrounds the annular rib 34 of the'cylinder head and which has the vertical shoulder 33 engaging this rib 34,

3 forms in efiect an expansion control ring adapted,

to restrain outward expansion relative to the cylinder. A gasket 35 is interposed between the adjacent sur--v during operation,

faces of the portions 28b and -3|. This gasket may be of the copper-asbestos type 'ap able' of sustaining high temperatures and pressure4-an'd is drawn down tightlywhen the cylinder head an annularreces's 32 thus connecting the jackets 24 together at the water tight joint formed by the communication respect to the jacket "20b overlying the supporting boss 39 and engagcasefl The "cylinder head vmay be drawn down tightly tothe crankcase or jacket 24 by suitable nutsapplied to the upper ends of the bolts 38, and 28 tightly gasket 30. The upper end of the jacket 24 is formed with an inwardly projecting boss 39 providihga ledge adapted tosupport the flange 20b of the'cyli'nder20. This boss 39 at its upper edge is provided with a series of 'ducts 39a providing betweenthe outer chamber 29 andv the chamber 25 for the flow of coolant between these chambers.) The boss is also cut away at intervals at 39b toprovide additional communic'ating -passages-between the chambers 25 and 29. Thus-, the cylinder 20 is positioned with 24 by means of its iflange ing the upper edge thereof, as shown particularly in It will, therefore, be seen that when the cylinder headis drawn down tightly through the medium of the bolts 38 the gasket 35 will be compressed to provide a water tight joint and the rib-like portion 34 of the wall 3|0f the cylinder head will fit snugly within the recess 32.

The cylinder head is formed with a generally frusto-conical recess 40 within which is mounted "a rotatable valve or rotor 4| which is also of generally frusto-conlcalconstruction having tapering outwardly converging walls corresponding generally in shape to the innerwalls of the recess 40." The botton'ior inner :wall 4|a of the valve is preferably tapered so as to correspond substantially to the taper of the piston head, the construction beingsuch that the piston head'will approach very closely the bottom of the valve. when the piston is atthe outer end of its stroke; I

The valve member 4I' is'f'ormed with a, side port "43 -communicating with the combustion chamber 42 and. adaptedto register successively during rotation of the'valve witha spark plug 44, an exhaust passage or conduit 45, and an intake conduit or passage 46 in the cylinder head,

the direction of rotation of the valve being indicated by the arrow in Fig. 3. As alsoshown in this figure, the liquidcoolant chamber 29 has extensions 29a in the cylinder head extending substantially around the valve member 4| and also extending along and in the height of the outer walls of the exhaust and intake passages 45 and 45. Another portion 29b of the coolant chamber extends through the dividing wall between these passages. From this construction it will be seen that substantially all portions of the cylinder, cylinder head, valve'and'intake and exhaust passages, which are subjected to. heating during operation, are exposed to the cooling effect of-the liquid circulated through the water jackets. The coolant is'preferabIy introduced into the lower end of the chamber 25, circulated upwardly through the communicating chambers, which have a common outlet in the cylinder head.

In addition to the side port 43 the valve 4| has a central port or opening 41 at its inner end communicating with the cylinder. The valve member 4| is also formed with a cooling chamber 48 extending entirely around the combustion This cooling chamber of the .valvemember.

' which is sealed into the chamber is adapted to receive any suitable cooling medium su'ch,-for example, as metallic sodium,

chamber bymeans of an expanding plug 48a." v t In the present embodiment the valve or rotor 41 is driven at one-half engine or crankshaft speed. It is provided-with a projecting stem 49 6 I I wall 49 of the valve housing and may be constructed and serve 'thepurposes in accordance with copending application Serial No. 495,260. .The embodiment illustrated ln'Fig: differs from the precedingemb'o'diment in that the Joint between the wallsof the cylinderja'cket 24 and through the medium of which the driving mechanism for the 'valve is connected. The valve housing portion 39 of the cylinder head ispror vided with an annular recess 50 in its outer end receive a threaded stud or bolt 56 which carries the cylinder headjacket 28 lies below ithe wrist pin 2la when the piston 2| is at its extreme outer position. within the cylinder-20. In this embodiment the cylinder head jacket 28 has a dependingskirt H which terminates well below the outer' end of the cylinder.

therefore, shortened as compared win its con-' The jacket 24 is,

struction'in' Fig. l anda'sealing' gasket 12 is interposed between the meeting edges of these Jackets and 'at a point below the wrist pin 2|a.

The jacket members is provided with an infwardly projecting annular flange 13' providing a a'nut 56a engageable with the coupling disk 53v and adapted to be tightened to draw down the disk and maintain its teeth 54 inconstant mesh with the teeth on theouter end of the valve stem. The spring'52 is, therefore, held underconstant compression so as to yieldin'gly hold the valve upwardlywithin the frusto-conical recess 40 in the valve housing. The strength of this spring and the amount of preloading thereof, is such that the effort exerted by thespring to raise the valve within the valve housing is sufil-.

cient to substantially offset or equal the effort exerted during, the suction stroke of the, piston I to draw the valve downwardly .and away from The coupling" disk 53 is provided with external teeth 55 meshing with internal teeth am on a ring gear 51. This gear in turn hasv external teeth 51b meshing with the teeth of a valve tending top shaft 16L The cylinder head is formed with a housing 5-9 provided with a removable closure 60 for housing the driving meshanism located in the cylinder head. The top shaft 6| at one end thereof carries a gear a 62 meshing with a gear 63 secured tothe upper end of a tower shaft. This tower shaft extends through'a tubeor housing! and carries at its lower end a gear 66 meshing with a gear 61 secured to the crankshaft 23 613 the engine.

It will be noted that the bottom of thevalve -member 4l has a downwardly and outwardly tapering contour a corresponding'to the tapering contour of the piston head. This tapering seat for a sleeve surrounding theouter end of the'cylind er and spaced-therefrom to provide a chamber 15 for liquid coolant. The sleeve 14 is also spaced from the jacket portion H so as to provide a chamber 16 for liquid coolant. The

chamber 15 is "in constant communication with the chamber 25 through the medium of ducts or passages", and the chamber-16 is in constant communication 'with'the chamber 15 through the medium" of transverse slots or ducts to the ducts 39a illustrated in Fig. 4.

From the foregoing construction it will be seen that the cylinder flange :20!) is supported upon the projecting sleeve orflange l3 ofthe fixed Jac ket 24 through themedium of the sleeve 14, the latter providing communication at all times:

between the chamber 15 and the associated coolying'ehambers 16 and25, By virtue of the constructionillustrated in Fig. 5 it'is possible in "overhauling the engine to remove the piston :driving gear 58 secured to a longitudinally 'exwithout disconnecting it from the crankshaft. The construction'in this embodiment permits the cylinder head and cylinder to be removed relatively to the jacket 24 without disturbingthe piston, after which the pinila may be withdrawn to'perrnit removal of the piston; Other than the :foregoing' the construction of the enginein the embodiment of Fig. 5 corresponds substantially to that previously described.

bottom portion Me of the valve terminates at a point inward of the outer end of the cylinder .tained between the bevelled or tapering bottom portion 68 of the 'valve' and thebevelled end 68 of the cylinder wall so that at no timeduring "operation will the valve contact the end of the cylinder. This clearance will be maintained even during the suction stroke of the piston since, as previously stated, the loadingof the spring 52 is suflicient to: counteract the downward. pull on the valve during the suction stroke. The valve member is also preferably provided with an exterior relief area 10 extending entirely around the valve and substantially the height of th v side port 43. This annular relief area maybe formed either in' thevalve orin the,

wall in an outwardly and upwardly tapering or bevelled portion 68 which overlies the bevelled end 69 of the cylinder wall. A clearance of a few thousandths of an inch is at all times'ma'in- It'will: be seen that the present lnvention provides a veryaccuratecontrolgof the expansion; rates of the cylinder head valve housing 3| and rotatable valve*4l. This valve'housing and also the piston cyli'nder are surrounded by a jacket within which a liquid coolant is circulated, thus providing I substantially uniform dissipation of heat. In preferredpractice the cylinder head (includingthe valve housing) is made of 'an aluminurn alloy whereas the rotary valve and the cylinder are'formed of suitable ferrous alloys.

' Hencefthe valve housingwill have a greater rate of expansion than. either the. valve or cylinder, the latter two having substantially the same rate of expansion. i'Ordinarilyftherefom, the head will tend to-expand more rapidly or to a greater degree thanthe valve, thus increasing the clear ances between the valve and valve housing which will have the undesirable 'result of causing oil leakage especially during the suction stroke of the piston. However, in accordance with the present invention the valve housing has an annularrib seated in'the recess 32 of the cylinder and abutting against the shoulder 33. This shoulder actsas a restrainingabutment preventing outward movement of the'valve housing relative to the cylinder. Hence, a constant control 'over'the expansion of the housing with relation 18 similar to the cylinder and valve is maintained and the desired operating clearances between the valve and valve housing are held substantially uniform during operation. Much improved operation is,

therefore, achieved while reducing materiallythe.

'with a generally frusto-conical cavity, a generally frusto-conical valve in said cavity, said cylinder and valve being formed of ferrous metal and said cylinder head being formed of'metal having a greater coefllcient of thermal expansion, and meanson the cylinder engaging said head for restraining lateral expansion of said head at the locality of its bearing engagement with the valve at the inner end of the latter.

2. In an internal combustion engine, a cylinder, 3. cylinder head having a portion provided with a generally frusto-conical cavity, a general ,ly frusto-conical valve in said cavity, said cylinder and valve being formed of ferrous metal and said cylinder head being formed of metal having a greater coefficient of thermal expansion, and annular means on said cylinder engaging said head for restraining lateral expansion of said head at the locality of its bearing engagement with the valve at the inner end of the latter.

3. In an internal combustion engine, a cylinder,a cylinder head having a. portion provided with a generally frusto-conical cavity, a generally frusto-conical valve in said cavity, said cylinder and valve being formed of ferrous metal and said cylinder head being formed of metal having a greater coefficient of thermal expansion, and an abutment ring on said cylinder engaging the head adjacent the locality of its bearing engagement with the inner end of the valve for restraim ing lateral expansion of the head.

4. In an internal combustionengine, a cylinder, a cylinder head having a portion provided with a generally frusto-conical cavity, a. generally frusto-conicalvalve in said cavity, said cylinder and valve being formed of ferrous metal andsaid cylinder head being formed of metal having a greater coeflicient of thermal expansion, and means controlled by the cylinder engaging said head for maintaining the expansion rate of the head adjacent the inner end of the valve sub stantially, corresponding to that of the valve.

5. In an internal combustion engine, a cylinder,

a cylinder head having a portion provided with a generally frusto-conical cavity, a generally frusto-conical valve in said cavity, said cylinder and valve being formed of ferrous metal and said cylinder head being formed of metal having a greater coeflicient of thermal expansion, and

abutment means controlled by the cylinder for restraining any substantial lateral expansion of the inner wall portion of said cavity relatively to the adjacent portions of the valve, said abut ment meanscomprising an annular shoulder on the outer end of the cylinder abutting against an annular portion of the head fitting within said shoulder.

6. In an internal combustion engine, a cylinder, a cylinder head having a portion provided with a ,geneoally frusto-conical cavity, a generally frusto-c nical valve in said cavity, said cylinder head b'eing formed of metal having a. greater coefficient of thermal expansion than the metal of said cylinder and valve, and an abutment ring on said cylinder engaging the head adjacent the locality of its bearing engagement with the 'head, a-liquid cooling means on ,the first inner end of the valve for restraining lateral expansion of the head.

7. In aninternal combustion engine,-a cylinder, a cylinder head having a portion provided with a generally frusto-conical cavity,'a generally frusto-conical valve in said cavity, said cylinder head being formed of metal having a great-- ercoefflcient of thermal expansion than the metal of, said cylinder and valve, and means controlled by the cylinder and abutting said head for maintaining the expansion rate of the'head adally frusto-conical valve in said cavity, said cylinder head being formed of metal having a greater coefiicient ofthermal expansion than the metal of said cylinder and valve, and abutment means controlled by the cylinder for restraining any substantial lateral expansion of the inner wall portion of said cavity relatively to the adjacent portions of the valve.

9. In an internal combustion engine, a cylinder, 2. cylinder head, a rotatable valve in said jacket surrounding the cylinder, a second liquid cooling jacket on the head surrounding said valve, outwardly projecting ,fiange means on the cylinder terminating in spaced relation to said second'jacket, projecting named jacket underlying said flange means at a distance therebelow, a member interposed between said projecting means and flange means for supporting the cylinder on said first namedjacket, sealing means between said flange means and the cylinder head, sealing means between said jackets, and means for drawing down the head upon said cylinder and firstnamed jacket to compress said sealing means.

10. In an internal combustion engine, a cylinrder head having a generally frusto-conical cav-' ity,

uid cooling chamber communicating with the first named chamber with the outer end of the jacket in sealingfengagement with the inner end of said outer wall, the outer end of the cylinder and the inner end of said inner wall having abutting means adjacent the inner end: of the valve for restraining lateral expansion of the head adjacent the inner end of the valve, said abutting means being separated from said outer wall by saidfirst named cooling chamber.

11. In an internal combustion engine, 9. cylinder head having a generally frusto-conicalcavity, agenerally frusto-conical rotatable valve in said cavity, said head comprising spaced outer and inner walls extending around th valve providing a liquid cooling chamber, a cylinder, a

' jacket surrounding the cylinder providing a liq- 12. In an internal combustion engine, a cylin- 9 der head having a generally frusto-conical cavity, a generally frusto-conical rotatable valve in said cavity. said head comprising spaced outer and inner walls extending around the valve providing a liquid cooling chamber, a cylinder, 9. jacket surrounding the cylinder providing a liquid cooling chamber communicating with the first named chamber with the outer end of the jacket in sealing engagement with the inner end 01 said outer wall, the inner end of said inner wall having an annular recess around the outside there I of and the outer end of the cylinder having an annular abutment fitting into said recess opposite the inner end of the valve and separated from said outer wall by said first named cooling chamber.

13. In an internal combustion engine, a cylinder head having a generally frusto-conical'cavity,

a. generally frusto-conical rotatable valve in said cavity, said head comprising spaced outer and inner walls extending around the valve providing a liquid cooling chamber, a cylinder having a lesser coeflicient of thermal expansion than said cylinder head, a jacket surrounding the cylinder providing a liquid cooling chamber communicating with the first named chamber with the outer end of the jacket in sealing engagement with the viding a liquid cooling chamber, a cylinderhaving a lesser coefficient of thermal expansion than said-cylinder head, a jacket surrounding the cylinder providing a liquid cooling chamber communicating with the first named chamber with the outer end of the jacket in sealing engagement with the inner end of said outer wall, the innenend of said inner wall having an annular recess and the outer end of the cylinder having an annular abutment fitting into said recess and exposed to the cooling liquid in said first chamber and also providing means for restraining lateral expansion of the head adjacent the inner end of the valve.

the valve at the inner end of the latter, and a liquid cooling chamber in the head within which said restraining means is exposed to cooling fluid.

16. In an internal combustion engine, a cylinder, a cylinder head having a portion provided with a generally frusto-conical cavity, a generally frusto-conical valve in said cavity, said cylinder and valve being formed of'ferrous metal and said cylinder head being formed of metal having a greater coemcient of thermal expansion, means on said cylinder engaging the head adjacent the inner end of said cavity for restraining lateral expansion of said head at the locality of its bearing engagement with the valve at the inner end of the latter, and a liquid cooling chamber in the head within which said restraining means is exposed to cooling fluid.

1'7. In an internal combustion ngine, a cylinder, 9. cylinder head having a portion provided with a generally frusto-conical cavity, a generally frusto-conical valve in said cavity, said cylinder and valve being formed of ferrous metal and said cylinder head being formed of metal having a greater coeflicient of thermal expansion, an abutment ring on said cylinder engaging the head adjacent the locality of itsbearing engagement with the inner end of the valve for restraining lateral expansion of the head, and a liquid coolingcham- 15. In an internal combustion engine, a cylin- I der, a cylinder head having a portion provided with a generally frusto-conical cavity, a generally frusto-conical valve in saidcavity, said cylinder and valve being formed of ferrous metal and said cylinrler head being formed of metal having a greater coefilcient of thermal expansion, abutting means interposed between the cylinder and head .ior restraining lateral expansion of said head at the locality of its bearing engagement with her in the head within which said abutment ring is exposed to cooling fluid.

18. In an interval combustionengine, a cylinder, a, cylinder head having a portion provided with a generally frusto-conical cavity, a gener* ally frusto-conical valve in said cavity, said cylinder and valve being formed'of ferrous'metal and said cylinder head being formed of metal having a greater coeflicient of thermal expansion, abutment means controlled by the cylinder for restraining any, substantial lateral expansion of the inner'wall portion of said cavity relatively to the-adjacent portions of the valve, said abutment means. comprising'an annular shoulder on the outer end of the cylinder abutting against an annular portion of the head fitting within said shoulde'igand a liquid cooling chamber in the head within which said shoulder is exposed to cooling fluid. I v

19. In an internal combustion engine, a cylinder, a cylinder head having a portion provided with a generally frusto-conical cavity, a generally frusto-conical valvein said cavity, said cylinder head being formed of metal having a greater coefiicient of thermal expansion than the metal of said cylinder and valve, an abutment ring on said cylinder engaging the head adjacent the locality of its bearing engagement with the inner end of the valve for restraining lateral expansi on of the head, and a liquid cooling chamber in the head within which'said abutment ring is exposed to cooling fluid.

CLARENCE E. FRANK. 

